The design of the study allowed for comparison of parental alcohol dependence (AD) with risk status (multiplex alcohol dependence or control). Participant offspring had been identified through families containing two adult same-sex alcoholic siblings. Some offspring from high risk families did not have alcoholic parents though they had multiple aunts, uncles or grandparents with alcoholism. Results obtained using presence or absence of multiplex familial risk status are largely consistent with those obtained when analyses are performed using the presence or absence of parental alcoholism. In other words, youngsters from multiplex pedigrees have elevated risk for a number of disorders even if they do not have an AD parent.
